Mask-less laser direct imaging system

A reflective mask-less laser direct imaging system comprising a platform (1), a carrier (11) movable on the platform (1) along a Y-axis and operable to carry a substrate (4) coated with a photosensitive layer (41), a gantry (12) supported on the platform (1), and a laser-based imaging device (2) connected to the gantry (12) and operable to scan the photosensitive layer (41) of the substrate (4) while the carrier (11) is moving the substrate (4) under and past the gantry (12), wherein the laser-based imaging device (2) comprises:

• laser sources (21) arranged along an X-axis and operable to emit parallel laser beams (211);
• focusing lenses (22) for focusing the laser beams (211) onto the photosensitive layer (41) of the substrate (4) from the laser sources (21);
• a reflective scanner (23) comprising:
• two bearings (231) connected to the gentry (12);
• a polygonal mirror (232) comprising two terminal sections supported on the bearings (231) and facets (232a) for reflecting the laser beams (211) to the substrate (4) from the focusing lenses (22), wherein each of the facets (232a) does not extend parallel or perpendicular to the optical axis (220) of the corresponding focusing lens (22) while reflecting the corresponding laser beam (211) that go through the corresponding focusing lens (22);
• and
• a motor (M) operatively connected to one of the terminal sections of the polygonal mirror (232);
• and
• a compensating lens (24) located between the polygonal mirror (232) and the substrate (4) and comprising a convex face (241) pointed at the polygonal minor (232) and a planar face (242) pointed at the substrate (4), wherein the laser beams (211), which come from the polygonal mirror (232), enter the compensating lens (24) through the convex face (241) and leave the compensating lens (24) through the planar face (242) before heading for the photosensitive layer (41) of the substrate (4).